Author + information
- Kiyotake Ishikawa,
- Shin Watanabe,
- Kenneth Fish and
- Roger Hajjar
Background: Left ventricular (LV) unloading may improve coronary flow and myocardial perfusion by increasing cardiac output and reducing LV wall stress. Whether LV unloading improves myocardial perfusion in a post-MI setting is not known. Our goal was to determine if LV unloading with an Impella CP increases coronary flow and myocardial perfusion in a sub-acute myocardial infarction (MI).
Methods: A large anterior transmural MI (infarct size: 26.1±4.1%) was induced by occluding the proximal left anterior descending artery (LAD) for 90 minutes in Yorkshire pigs (n=5), followed by a thrombus injection through the balloon lumen. Two-weeks after the MI, animals underwent LV unloading with an Impella CP for 2 hours. Epicardial coronary flow was assessed by coronary flow wire and myocardial perfusion was assessed using fluorescent microspheres.
Results: LV unloading with maximal pump support for 2 hours resulted in an increase in total cardiac output (3.1 to 3.9 L/min). Impella support significantly reduced end-diastolic volume (109±17 to 85±12 mL, P=0.02) and end-diastolic pressure (29.3±5.6 to 19.2±6.9 mmHg) resulting in a significant decrease in LV end-diastolic wall stress (infarct: 34.4±5.5 to 20.2±5.2 kdynes/cm2, P=0.03; remote: 32.4±8.6 to 19.3±6 kdynes/cm2, P=0.03). Coronary flow increased acutely and remained elevated after 2 hours. Compared to the baseline, myocardial perfusion significantly increased within the infarct zone as measured by fluorescent microspheres (+114±90%, P=0.02), while perfusion of the remote non-ischemic myocardium did not change (-1.2±33%, P=0.89). There was a linear relationship between infarct wall stress and the perfusion of infarct zone (R2=0.48, P=0.027), whereas no clear relationship was observed in the infarct border zone (R2=0.01, P=0.77) and remote zone (R2=0.01, P=0.78).
Conclusions: LV unloading using an Impella CP increases coronary flow and perfusion of infarcted myocardium for at least 2 hours. Infarct perfusion is predominantly determined by the LV wall stress.
Poster Hall, Hall C
Saturday, March 18, 2017, 9:45 a.m.-10:30 a.m.
Session Title: Novel Developments in Acute Coronary Syndromes
Abstract Category: 15. Interventional Cardiology: ACS/AMI/Hemodynamics and Pharmacology
Presentation Number: 1194-164
- 2017 American College of Cardiology Foundation